centralize open isle domain

src/main/java/com/openisle/controller/AdminUserController.java

@@ -4,6 +4,7 @@ import com.openisle.model.User;
 import com.openisle.service.EmailSender;
 import com.openisle.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
@@ -13,6 +14,8 @@ import org.springframework.web.bind.annotation.*;
 public class AdminUserController {
     private final UserRepository userRepository;
     private final EmailSender emailSender;
+    @Value("${app.website-url}")
+    private String websiteUrl;
 
     @PostMapping("/{id}/approve")
     public ResponseEntity<?> approve(@PathVariable Long id) {
@@ -20,7 +23,7 @@ public class AdminUserController {
         user.setApproved(true);
         userRepository.save(user);
         emailSender.sendEmail(user.getEmail(), "Registration Approved",
-                "Your account has been approved. Visit: https://www.open-isle.com");
+                "Your account has been approved. Visit: " + websiteUrl);
         return ResponseEntity.ok().build();
     }
 
@@ -30,7 +33,7 @@ public class AdminUserController {
         user.setApproved(false);
         userRepository.save(user);
         emailSender.sendEmail(user.getEmail(), "Registration Rejected",
-                "Your account request was rejected. Visit: https://www.open-isle.com");
+                "Your account request was rejected. Visit: " + websiteUrl);
         return ResponseEntity.ok().build();
     }
 }